1. Field of the Invention
This present invention relates to a pen or stylus for inputting commands to the user's interface shown on touch screen, and in particular as the touch screen is in form of a capacitive type, its corresponding touch screen pen.
2. Description of the Prior Art
Due to high satisfactions of functionalities of touch screen input apparatus, the mobile phones or computers of the type have been widely quested by fans for high-tech devices. Some examples of these are iPhone, iPad marketed by Apple (Brand Name)
In general, to operate those apparatus, the users use their bare fingers. Under the typical situations, the touch screen pens are not needed at all. However, different people have different diameter size of each finger. As the finger is used to write alphabets or multiple-stroke characters (Chinese) on the touch screen to make word-notes, larges thumbs or large forefingers might cause difficulty during the character-recognition process. In addition, in summer days users easily sweat a lot making finger-input an unpleasant experience. Furthermore, some of female teenagers of this generation used to wear artificial colorful fingernails which are usually longer than their front part of each finger. Under those special conditions, the fingers can not command the apparatus well.
With regard to the resistive type touch screen, the corresponding touch screen pen tips can be made much smaller which allows more icons of smaller size on the user interface. But the pen tips of resistive type pen can not be utilized on the capacitive type touch screen due to entirely different operational principles.
There are also two different categories of capacitive type touch screen pen. One kind of them uses the static electricity of human body and conveys the static electricity via touch screen pen to the surface of touch screen altering the voltage of the substrates constituting the capacitive type touch screen. No command operation may be made when the users wear the gloves during the severe winter days.
Another type of them has design inside itself which induces electric field used to alter the voltage of the substrates constituting the capacitive type touch screen. The command operations may still be made even the users wear the gloves during the severe winter days.
DAGI (Brand Name) capacitive touch screen pen found in the marketplace with transparent pen-tip has following virtues: (1) Blocking the users' sight focus over the interface is avoided, the effective prevention of accidental touch (actuation) is possible; (2) Consumption of no power; (3) High precision inputs suitable for selecting and activating smaller icons while surfing the Web pages and for word processing purpose; (4) Suitability for character recognition. However, there is a need for improving the life cycle of the transparent pen-tip.
Nokia (Brand Name) has marketed the touch screen pen of part No. SU-36 which is applicable to mobile phone models of Nokia N8, X6 and also to other brands implementing the capacitive type touch screen.
The touch screen pen ST C400 (Brand Name) of Htc (Brand Name) utilizes magnetized pen-tip to produce corresponding current on the capacitive type touch screen while touching on the screen to manipulate the interface.
Taiwan Songtak Co. has added specialized ingredient into the PU material of pen-tip to extend the life cycle of the touch screen pen. This maker emphasizes the usage of the touch screen pen even the users wear gloves in winter days.
The touch screen pens TOUCH, TOUCH2, TOUCH3 (Brand Name) for Apple (Brand Name) iPhone 2G, 3G, 3GS have pen-tip utilizing the electrically-conductive rubber or soft foam. It is known that the pen-tip is made of carbon-rich rubber or soft foam. The surface of the touch screen should be kept clean and slick for smooth operation of the conductive rubber or soft foam.
Since the carbon-rich rubber or foam is anti-slip, the possible drawbacks as they are used for the pen-tips include the aging of the elasticity. To improve the electric conductive capability of rubber, carbon content should be high enough that makes the pen-tip harder easily scratching the touch screen.
U.S. Pat. No. 5,914,708 discloses a pen-tip made of the soft foam which is electrically-conductive.
To meet the needs which cure the defects mentioned above for the touch screen pen used with the capacitive type touch screen, the present invention intends to provide a novel solution.